README
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Lex-go
This is an extract from FoundationDB (RIP) client library. It allows to compose lexicographic keys and manipulate them.
See LICENSE file for the license
Documentation
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Overview ¶
Package lex contains functions to compose and manipulate lexicographically sortable keys. It is forked from FoundationDB API libs (RIP).
Index ¶
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
This section is empty.
Types ¶
type ExactRange ¶
type ExactRange interface {
// LexRangeKeys returns a pair of keys that describe the beginning and end
// of a range.
LexRangeKeys() (begin, end KeyConvertible)
// An object that implements ExactRange must also implement Range
// (logically, by returning FirstGreaterOrEqual of the keys returned by
// LexRangeKeys).
Range
}
An ExactRange describes all keys between a begin (inclusive) and end (exclusive) key. If you need to specify an ExactRange and you have only a Range, you must resolve the selectors returned by (Range).LexRangeKeySelectors to keys using the (Transaction).GetKey method.
Any object that implements ExactRange also implements Range, and may be used accordingly.
type Key ¶
type Key []byte
Key represents a lexicographically-ordered sequence of bytes. Key implements the KeyConvertible interface.
type KeyConvertible ¶
type KeyConvertible interface {
LexKey() Key
}
A KeyConvertible can be converted to a lexicographic Key.
type KeyRange ¶
type KeyRange struct {
Begin, End KeyConvertible
}
KeyRange is an ExactRange constructed from a pair of KeyConvertibles. Note that the default zero-value of KeyRange specifies an empty range before all keys in the database.
func (KeyRange) LexRangeKeySelectors ¶
func (kr KeyRange) LexRangeKeySelectors() (Selectable, Selectable)
LexRangeKeySelectors allows KeyRange to satisfy the Range interface.
func (KeyRange) LexRangeKeys ¶
func (kr KeyRange) LexRangeKeys() (KeyConvertible, KeyConvertible)
LexRangeKeys allows KeyRange to satisfy the ExactRange interface.
type KeySelector ¶
type KeySelector struct {
Key KeyConvertible
OrEqual bool
Offset int
}
KeySelector represents a description of a key in a FoundationDB database. A KeySelector may be resolved to a specific key with the GetKey method, or used as the endpoints of a SelectorRange to be used with a GetRange function.
The most common key selectors are constructed with the functions documented below. For details of how KeySelectors are specified and resolved, see https://foundationdb.com/documentation/developer-guide.html#key-selectors.
func FirstGreaterOrEqual ¶
func FirstGreaterOrEqual(key KeyConvertible) KeySelector
FirstGreaterOrEqual returns the KeySelector specifying the lexigraphically least key present in the database which is lexigraphically greater than or equal to the given key.
func FirstGreaterThan ¶
func FirstGreaterThan(key KeyConvertible) KeySelector
FirstGreaterThan returns the KeySelector specifying the lexigraphically least key present in the database which is lexigraphically strictly greater than the given key.
func LastLessOrEqual ¶
func LastLessOrEqual(key KeyConvertible) KeySelector
LastLessOrEqual returns the KeySelector specifying the lexigraphically greatest key present in the database which is lexigraphically less than or equal to the given key.
func LastLessThan ¶
func LastLessThan(key KeyConvertible) KeySelector
LastLessThan returns the KeySelector specifying the lexigraphically greatest key present in the database which is lexigraphically strictly less than the given key.
func (KeySelector) LexKeySelector ¶
func (ks KeySelector) LexKeySelector() KeySelector
LexKeySelector is a dummy method
type Range ¶
type Range interface {
// LexRangeKeySelectors returns a pair of key selectors that describe the
// beginning and end of a range.
LexRangeKeySelectors() (begin, end Selectable)
}
A Range describes all keys between a begin (inclusive) and end (exclusive) key selector.
type Selectable ¶
type Selectable interface {
LexKeySelector() KeySelector
}
A Selectable can be converted to a FoundationDB KeySelector. All functions in the FoundationDB API that resolve a key selector to a key accept Selectable.
type SelectorRange ¶
type SelectorRange struct {
Begin, End Selectable
}
SelectorRange is a Range constructed directly from a pair of Selectable objects. Note that the default zero-value of SelectorRange specifies an empty range before all keys in the database.
func (SelectorRange) LexRangeKeySelectors ¶
func (sr SelectorRange) LexRangeKeySelectors() (Selectable, Selectable)
LexRangeKeySelectors allows SelectorRange to satisfy the Range interface.
Source Files
Directories
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| Path | Synopsis |
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Package subspace provides a convenient way to use FoundationDB tuples to define namespaces for different categories of data.
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Package subspace provides a convenient way to use FoundationDB tuples to define namespaces for different categories of data. |
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Package tuple provides a layer for encoding and decoding multi-element tuples into keys usable by FoundationDB.
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Package tuple provides a layer for encoding and decoding multi-element tuples into keys usable by FoundationDB. |